WO2023084681A1

WO2023084681A1 - Laser machining system, laser machining method, and method for manufacturing electronic device

Info

Publication number: WO2023084681A1
Application number: PCT/JP2021/041508
Authority: WO
Inventors: 康文川筋; 理若林; 章義鈴木
Original assignee: ギガフォトン株式会社
Priority date: 2021-11-11
Filing date: 2021-11-11
Publication date: 2023-05-19
Also published as: US20240272444A1; JPWO2023084681A1; CN118076456A

Abstract

This laser machining system includes: a laser device for outputting pulsed laser light; a divergence adjuster for adjusting a first beam divergence of the pulsed laser light in a first direction, and a second beam divergence in a second direction intersecting the first direction; a measuring instrument for measuring the first and second beam divergences of the pulsed laser light that has been processed by the divergence adjuster; a diffraction optical element for branching the pulsed laser light that has been processed by the measuring instrument; and a processor for controlling the divergence adjuster, on the basis of the result of measurement of the first and second beam divergences by the measuring instrument, such that the first and second beam divergences approach respective target values.

Description

Laser processing system, laser processing method, and electronic device manufacturing method

The present disclosure relates to a laser processing system, a laser processing method, and an electronic device manufacturing method.

In recent years, semiconductor exposure apparatuses have been required to improve their resolution as semiconductor integrated circuits have become finer and more highly integrated. For this reason, efforts are being made to shorten the wavelength of the light emitted from the exposure light source. For example, as gas laser devices for exposure, a KrF excimer laser device that outputs laser light with a wavelength of about 248 nm and an ArF excimer laser device that outputs laser light with a wavelength of about 193 nm are used.

The excimer laser beams output from the KrF and ArF excimer laser devices have pulse widths of several tens of nanoseconds and short wavelengths of about 248 nm and about 193 nm. be able to.
Chemical bonds in polymeric materials can be broken by excimer laser light with photon energy higher than the bond energy. Therefore, it is known that the excimer laser beam enables non-heating processing of polymer materials, resulting in a beautiful processed shape.
It is also known that materials such as glass and ceramics have high absorptance for excimer laser light, and therefore even materials that are difficult to process with laser light in the visible or infrared region can be processed with excimer laser light.

Japanese Patent Publication No. 2018-501115

overview

In one aspect of the present disclosure, a laser processing system includes a laser device that outputs pulsed laser light, a first beam divergence in a first direction of the pulsed laser light, and a second direction that intersects the first direction. a second beam divergence, a divergence adjuster for adjusting the divergence adjuster, a measuring device for measuring the first and second beam divergence of the pulsed laser light that has passed through the divergence adjuster, and the pulsed laser light that has passed through the measuring device a diffractive optical element for splitting; and a processor for controlling a divergence adjuster so that the first and second beam divergence approaches respective target values based on the measurement result of the first and second beam divergence by the measuring instrument. ,including.

In another aspect of the present disclosure, a laser processing method includes outputting pulsed laser light from a laser device, and performing a first beam divergence in a first direction of the pulsed laser light and a second beam divergence crossing the first direction. A second beam divergence in the direction of and a pulsed laser beam is made incident on a divergence adjuster that adjusts the divergence adjuster to measure the first and second beam divergence of the pulsed laser light that has passed through the divergence adjuster with a measuring instrument. Based on the measurement results of the first and second beam divergence by the instrument, the divergence adjuster is controlled so that the first and second beam divergence approaches respective target values, and the pulsed laser light that has passed through the measuring instrument is adjusted. It includes branching with a diffractive optical element and irradiating the workpiece.

In another aspect of the present disclosure, an electronic device manufacturing method includes a laser device that outputs pulsed laser light, a first beam divergence in a first direction of the pulsed laser light, and a crossing of the first direction. a second beam divergence in a second direction; A divergence adjuster is operated so that the first and second beam divergence approaches respective target values based on the results of measurement of the first and second beam divergence by the diffractive optical element that splits the pulsed laser beam and the measuring instrument. a laser processing system including a processor for controlling laser processing of the interposer substrate to fabricate the interposer; coupling the interposer and the integrated circuit chip to electrically connect each other; coupling the interposer and the circuit board to each other; Including electrically connecting.

Several embodiments of the present disclosure are described below, by way of example only, with reference to the accompanying drawings.
FIG. 1 schematically shows the configuration of a laser processing system in a comparative example. FIG. 2 shows a beam cross section perpendicular to the optical path axis of the pulsed laser light output from the output coupling mirror. FIG. 3 shows a cross section of branched light of pulsed laser light incident on a workpiece in a comparative example. FIG. 4 schematically shows the configuration of the laser processing system in the first embodiment. FIG. 5 shows a beam cross-section of pulsed laser light measured by an image sensor included in the measuring instrument, together with its light intensity distribution in the V and H directions. FIG. 6 is a flow chart showing a laser processing method according to the first embodiment. FIG. 7 is a flowchart showing the details of the process of calculating control parameters. FIG. 8 is a flow chart showing details of processing for feedback control of beam divergence and beam pointing. FIG. 9 shows a cross section of branched light of pulsed laser light incident on a workpiece in the first embodiment. FIG. 10 schematically shows the configuration of a laser processing system in a modified example. FIG. 11 schematically shows the configuration of a laser processing system in the second embodiment. FIG. 12 is a plan view of the mask in the second embodiment. FIG. 13 schematically shows the configuration of a laser processing system according to the third embodiment. FIG. 14 is a plan view of the mask in the third embodiment. FIG. 15 schematically shows a first example of a divergence adjuster. FIG. 16 schematically shows a first example of a divergence adjuster. FIG. 17 shows the principle by which the beam divergence is adjusted in the first example. FIG. 18 schematically shows a second example of a divergence adjuster. FIG. 19 schematically shows a second example of a divergence adjuster. FIG. 20 shows the principle by which the beam divergence is adjusted in the second example. FIG. 21 schematically shows a third example of a divergence adjuster. FIG. 22 schematically shows a third example of a divergence adjuster. FIG. 23 schematically shows a fourth example of a divergence adjuster. FIG. 24 schematically shows a fourth example of a divergence adjuster. FIG. 25 schematically shows a fifth example of a divergence adjuster. FIG. 26 schematically shows a sixth example of a divergence adjuster. FIG. 27 schematically shows a first example of an improved laser device. FIG. 28 schematically shows a second example of an improved laser device. FIG. 29 schematically shows a third example of an improved laser device. Figure 30 schematically shows a fourth example of an improved laser device. FIG. 31 schematically shows the configuration of an electronic device. FIG. 32 is a flow chart showing a method of manufacturing an electronic device.

embodiment

<Contents>
1. Laser Processing System According to Comparative Example 1.1 Configuration 1.1.1 Configuration of Laser Device 1 1.1.2 Configuration of Laser Processing Device 5 1.2 Operation 1.2.1 Operation of Laser Device 1 1.2. 2 Operation of Laser Processing Apparatus 5 1.3 Problem of Comparative Example 2. 2. Laser processing system including divergence adjuster 54 2.1 Configuration 2.2 Operation 2.2.1 Main flow 2.2.2 Calculation of control parameters 2.2.3 Beam divergence BDV and BDH and beam pointing BPV and BPH 2.3 Action 2.4 Laser processing system in which laser device 1b includes divergence adjuster 20 2.4.1 Configuration 2.4.2 Action 2.4.3 Action 3. 3. Laser processing system in which mask 65 is placed in the optical path of the light branched by diffractive optical element 63 and the image of mask 65 is transferred to workpiece SUB 3.1 Configuration and operation 3.2 Function 4. 4. Laser processing system for causing light that has passed through the mask 61 to enter the diffractive optical element 63 4.1 Configuration and operation 4.2 Action 5. 5. Details of divergence adjuster 5.1 Divergence adjuster 541 for adjusting beam divergence angle
5.1.1 Configuration and Operation 5.1.2 Operation 5.2 Divergence Adjuster 542 Adjusting Beamwidth
5.2.1 Configuration and operation 5.2.2 Action 5.3 Divergence adjuster 543 that once collects light and finely adjusts with a slit
5.3.1 Configuration and operation 5.3.2 Action 5.4 Divergence adjuster 544 for fine adjustment of lens position while focusing once
5.4.1 Construction and Operation 5.4.2 Operation 5.5 Divergence Adjuster 545 Including Optical Pulse Stretcher Misaligned in H Direction
5.5.1 Construction and Operation 5.5.2 Operation 5.6 Divergence Adjuster 546 Including Optical Pulse Stretcher Misaligned in the V Direction
6. 6. Improved Laser Apparatus 6.1 Laser Apparatus 1e with Attitude Controllable Optical Resonator
6.2 Laser Device 1f with Unstable Cavity
6.3 Laser device 1g including amplifier PA
6.4 Laser Device 1h Including Solid-State Lasers
6.4.1 Configuration 6.4.2 Operation7. others

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The embodiments described below show some examples of the present disclosure and do not limit the content of the present disclosure. Also, not all the configurations and operations described in each embodiment are essential as the configurations and operations of the present disclosure. In addition, the same reference numerals are given to the same components, and redundant explanations are omitted.

1. Laser Processing System According to Comparative Example 1.1 Configuration FIG. 1 schematically shows the configuration of a laser processing system in a comparative example. The comparative examples of the present disclosure are forms known by the applicant to be known only by the applicant, and not known examples to which the applicant admits. A laser processing system includes a laser device 1 and a laser processing device 5 .

1.1.1 Configuration of Laser Device 1 The laser device 1 is a gas laser device that outputs an ultraviolet pulse laser beam Out. The laser device 1 includes a laser chamber 10 , a power supply 12 , a rear mirror 14 , an output coupling mirror 15 , a monitor module 16 and a shutter 19 . These components are housed in the first housing 100 . The rear mirror 14 and the output coupling mirror 15 constitute an optical resonator.

A laser chamber 10 is arranged in the optical path of the optical resonator. A laser chamber 10 is provided with

windows

10a and 10b. The laser chamber 10 internally includes a pair of

discharge electrodes

11a and 11b. The laser chamber 10 is filled with a laser gas containing, for example, argon gas or krypton gas as a rare gas, fluorine gas as a halogen gas, and neon gas as a buffer gas.
The rear mirror 14 is composed of a highly reflective mirror, and the output coupling mirror 15 is composed of a partially reflective mirror. A pulsed laser beam Out is output from the output coupling mirror 15 .

Monitor module 16 includes a beam splitter 17 and an optical sensor 18 . The beam splitter 17 is positioned on the optical path of the pulsed laser beam Out output from the output coupling mirror 15 . The optical sensor 18 is positioned on the optical path of the pulsed laser beam Out reflected by the beam splitter 17 .
The shutter 19 is positioned on the optical path of the pulsed laser beam Out transmitted through the beam splitter 17 . The shutter 19 is configured to switch between passing and blocking the pulsed laser beam Out to the laser processing device 5 .

The laser device 1 further includes a laser control processor 13. The laser control processor 13 is a processing device including a memory 13a storing a control program and a CPU (central processing unit) 13b for executing the control program. Laser control processor 13 is specially configured or programmed to perform the various processes contained in this disclosure.

1.1.2 Configuration of Laser Processing Apparatus 5 The laser processing apparatus 5 includes an irradiation optical system 50 a , a frame 50 b , an XYZ stage 501 and a laser processing processor 53 .

The irradiation optical system 50a and the XYZ stage 501 are fixed to the frame 50b. A workpiece SUB is supported on a table 502 of an XYZ stage 501 .
In FIG. 1, the mutually orthogonal X and Y directions are parallel to the surface of the workpiece SUB. The Z direction is perpendicular to the surface of the workpiece SUB and parallel to the traveling direction of the pulsed laser beam Out incident on the surface of the workpiece SUB. A coordinate system defined by coordinate axes in the X, Y, and Z directions is defined as an XYZ coordinate system.

The workpiece SUB is, for example, an interposer substrate for manufacturing an interposer IP that relays an integrated circuit chip IC and a circuit substrate CS, which will be described later with reference to FIG. The interposer substrate is made of, for example, an electrically insulating material such as polymer material or glass material.

The irradiation optical system 50a includes high reflection mirrors 51a, 51b, and 51c, an attenuator 52, a diffractive optical element 63, and a condensing optical system 67. The high reflection mirrors 51 a , 51 b and 51 c , the attenuator 52 and the diffractive optical element 63 are housed in the second housing 500 . The condensing optical system 67 also serves as a window of the second housing 500 . The second housing 500 is connected to the first housing 100 via the optical path tube 200 . A pulsed laser beam Out output from the laser device 1 passes through the optical path tube 200 and enters the second housing 500 .

The high reflection mirror 51a is located in the optical path of the pulsed laser beam Out that has passed through the optical path tube 200 . The attenuator 52 is positioned in the optical path of the pulsed laser beam Out reflected by the high reflection mirror 51a. Attenuator 52 includes two partially reflecting

mirrors

52a and 52b and

rotating stages

52c and 52d. The rotary stages 52c and 52d are configured to change the transmittance of the attenuator 52 by changing the incident angle of the pulsed laser beam Out with respect to the partial reflection mirrors 52a and 52b, respectively.

The high reflection mirror 51b is positioned on the optical path of the pulse laser beam Out transmitted through the attenuator 52, and the high reflection mirror 51c is positioned on the optical path of the pulse laser beam Out reflected by the high reflection mirror 51b.

The diffractive optical element 63 is positioned on the optical path of the pulsed laser beam Out reflected by the high reflection mirror 51c. The diffractive optical element 63 has a large number of irregularities on its surface, and is configured to diffract the transmitted pulsed laser beam Out, thereby branching it into a plurality of optical paths.

The condensing optical system 67 is positioned on the optical path of the pulsed laser beam Out transmitted through the diffractive optical element 63 . The condensing optical system 67 converges the branched beams of the pulsed laser beam Out branched by the diffractive optical element 63 . The collection optics 67 have a focal length f ₆₇ . The condensing optical system 67 is desirably composed of an F.theta.

The laser processing processor 53 is a processing device including a memory 53a storing a control program and a CPU 53b executing the control program. Laser processing processor 53 is specially configured or programmed to perform various processes contained in this disclosure.

1.2 Operation 1.2.1 Operation of Laser Apparatus 1 In the laser apparatus 1 , the laser control processor 13 receives the data of the target pulse energy Et and the trigger signal from the laser processing processor 53 . The laser control processor 13 sets the voltage of the power supply 12 based on the target pulse energy Et and transmits a trigger signal to the power supply 12 .

When the power supply device 12 receives a trigger signal from the laser control processor 13, it generates a pulsed high voltage and applies it between the

discharge electrodes

11a and 11b.

When a high voltage is applied between the

discharge electrodes

11a and 11b, discharge occurs between the

discharge electrodes

11a and 11b. The energy of this discharge excites the laser gas in the laser chamber 10 to shift to a high energy level. When the excited laser gas then shifts to a lower energy level, it emits light with a wavelength corresponding to the energy level difference.

The light generated within the laser chamber 10 is emitted outside the laser chamber 10 through the

windows

10a and 10b. The light emitted from the window 10 a of the laser chamber 10 is reflected by the rear mirror 14 with high reflectance and returned to the laser chamber 10 .

The output coupling mirror 15 transmits and outputs part of the light emitted from the window 10 b of the laser chamber 10 and reflects the other part back to the laser chamber 10 .

In this way, the light emitted from the laser chamber 10 reciprocates between the rear mirror 14 and the output coupling mirror 15, and is amplified every time it passes through the discharge space between the

discharge electrodes

11a and 11b. A pulsed laser beam Out generated by laser oscillation in this manner is output from the output coupling mirror 15 .

FIG. 2 shows a beam cross section perpendicular to the optical path axis of the pulsed laser beam Out output from the output coupling mirror 15. FIG. FIG. 2 corresponds to a cross-sectional view taken along line II-II of FIG. The beam cross section of the pulse laser light Out corresponds to the shape of the discharge space between the

discharge electrodes

11a and 11b, and has a substantially rectangular shape elongated in the discharge direction between the

discharge electrodes

11a and 11b.

Let the L direction be the traveling direction of the pulse laser beam Out. Let the V direction be a direction perpendicular to the L direction and parallel to the long side of the beam cross section of the pulsed laser beam Out. Let the H direction be a direction perpendicular to both the L direction and the V direction. The H direction is parallel to the short side of the beam cross section of the pulsed laser beam Out. The V direction and H direction respectively correspond to the first and second directions in this disclosure. A coordinate system defined by coordinate axes in the L direction, the V direction, and the H direction is referred to as an LVH coordinate system.

Since the LVH coordinate system is defined with reference to the pulsed laser beam Out, when the pulsed laser beam Out is reflected, the relationship between the LVH coordinate system and the XYZ coordinate system described with reference to FIG. 1 changes, and , the LVH coordinate system itself is inverted. For example, when the pulse laser beam Out is reflected at right angles by the high reflection mirror 51a, the traveling direction of the pulse laser beam Out rotates around the H axis at right angles. In this case, each of the L and V directions rotates perpendicular to the XYZ coordinate system, and the V direction is reversed. However, it is assumed that the L direction, V direction, and H direction do not change depending on the projection optical system 68 described later.

Referring to FIG. 1 again, the monitor module 16 detects the pulse energy of the pulsed laser beam Out output from the output coupling mirror 15. The monitor module 16 sends the detected pulse energy data to the laser control processor 13 .

The laser control processor 13 feedback-controls the set voltage of the power supply 12 based on the pulse energy data received from the monitor module 16 and the target pulse energy Et data received from the laser processing processor 53 .

1.2.2 Operation of Laser Processing Apparatus 5 The XYZ stage 501 is adjusted so that the workpiece SUB is positioned at a focal distance _f67 from the condensing optical system 67 .
A pulsed laser beam Out output from the laser device 1 passes through the optical path tube 200 and enters the laser processing device 5 . The pulsed laser beam Out is reflected by the high reflection mirror 51a, transmitted through the attenuator 52, and then sequentially reflected by the high reflection mirrors 51b and 51c. The laser processing processor 53 sets a target value for the transmittance of the attenuator 52, and controls the

rotary stages

52c and 52d based on the target value.

The pulsed laser beam Out reflected by the high reflection mirror 51c is split into a plurality of optical paths by the diffractive optical element 63, and each of the split beams is focused on the surface of the workpiece SUB by the focusing optical system 67. When the workpiece SUB is irradiated with the branched light of the pulse laser beam Out, the surface of the workpiece SUB is ablated and laser-processed.

1.3 Problems of Comparative Example FIG. 3 shows a cross section of the branched light Out1 of the pulse laser light Out incident on the workpiece SUB in the comparative example. In the example shown in FIG. 3, the branched beam Out1 of the pulsed laser beam Out branched by the diffractive optical element 63 is incident on the surface of the workpiece SUB at positions corresponding to the vertices of the square lattice. The shape and arrangement of the branched light Out1 differ depending on the design of the diffractive optical element 63. FIG. A large number of fine holes can be formed in the workpiece SUB by irradiating the workpiece SUB with a large number of narrow branched beams Out1 respectively condensed by the condensing optical system 67 . This hole may be a through hole penetrating the workpiece SUB.

However, the cross-sectional shape of the branched light Out1 condensed by the condensing optical system 67 may not conform to the design of the diffractive optical element 63. For example, even if the diffractive optical element 63 is designed so that the cross-sectional shape of the branched light Out1 is a perfect circle, as shown in FIG. It can be oval. In this case, there is a possibility that desired laser processing cannot be achieved.

In the embodiment described below, by controlling the beam divergence BDV and BDH of the pulsed laser beam Out incident on the diffractive optical element 63, the cross-sectional shape of the branched beam Out1 incident on the workpiece SUB is adjusted to a desired shape. bring closer.

2. 2. Laser Processing System Including Divergence Adjuster 54 2.1 Configuration FIG. 4 schematically shows the configuration of the laser processing system in the first embodiment. In the first embodiment, the laser processing device 5a included in the laser processing system includes an actuator 51d, a divergence adjuster 54, a measuring instrument 55, and a shutter 59 in addition to the components shown in FIG. include.

The divergence adjuster 54 is configured to be able to adjust the beam divergence BDV in the V direction and the beam divergence BDH in the H direction of the pulse laser light Out. A specific configuration of the divergence adjuster 54 will be described later with reference to FIGS. 15 to 26. FIG. In the example shown in FIG. 4, the divergence adjuster 54 is arranged between the attenuator 52 and the high reflection mirror 51b. It may be placed at any position on the Out optical path.

The actuator 51d is attached to the high reflection mirror 51c, and is configured to be able to change the attitude of the high reflection mirror 51c. By changing the attitude of the high reflection mirror 51c, the traveling direction of the pulse laser beam Out reflected by the high reflection mirror 51c is changed. The beam pointings BPV and BPH are adjusted by adjusting the traveling direction of the pulsed laser beam Out. A beam steering device is composed of the high reflection mirror 51c and the actuator 51d. The beam steering device may be placed at any position on the optical path of the pulsed laser beam Out between the inside of the optical path tube 200 and the measuring device 55, but more preferably between the divergence adjuster 54 and the measuring device 55. is placed in the optical path of the pulsed laser beam Out.

Measuring device 55 includes beam splitter 56 , convex lens 57 , and image sensor 58 . The beam splitter 56 is positioned in the optical path of the pulsed laser light Out that has passed through both the divergence adjuster 54 and the beam steering device. The convex lens 57 is positioned on the optical path of the pulsed laser beam Out reflected by the beam splitter 56 . Convex lens 57 has a focal length f ₅₇ . Focal length f ₅₇ may be greater than focal length f ₆₇ of collection optics 67 . The image sensor 58 is positioned on the focal plane of the convex lens 57 on the optical path of the pulsed laser beam Out that has passed through the convex lens 57 . Here, the convex lens 57 may be a combined lens with a focal length of _f57 , which is a combination of a concave lens and a convex lens. The measuring device 55 is configured to be able to measure beam divergence BDV and BDH and beam pointing BPV and BPH of the pulsed laser light Out that has passed through both the divergence adjuster 54 and the beam steering device. Measurement of beam divergence BDV and BDH and beam pointing BPV and BPH will be described later with reference to FIG.

The shutter 59 is positioned on the optical path of the pulsed laser beam Out that has passed through the beam splitter 56 . The shutter 59 is configured to switch between passing and blocking the pulsed laser beam Out to the diffractive optical element 63 and the workpiece SUB.

FIG. 5 shows the beam cross-section S ₅₈ of the pulsed laser beam Out measured by the image sensor 58 included in the measuring instrument 55, together with its light intensity distribution in the V and H directions. 1/e of the peak value Imax of the light intensity I The full width in the V direction of the portion having the light intensity I of ² or more is the spot diameter D _CV in the V direction, and the full width in the H direction of the portion is the spot diameter D _CH in the H direction. and Alternatively, instead of 1/e ² , half value or 1/e may be used. Note that e is Napier's number. In the present disclosure, spot diameter is the diameter of the beam cross-section at the focal position. A beam waist diameter, which will be described later, is the diameter of the beam cross section at the beam waist position, and may differ from the spot diameter.

In this disclosure, beam divergence is defined as the beam width at the focal position divided by the focal length. The beam divergence BDV and BDH in the V and H directions are given by the following equations.
BDV= _DCV / _f57
BDH= _DCH / _f57
Beam divergence BDV and BDH correspond to first and second beam divergence in the present disclosure, respectively.

In this disclosure, beam pointings BPV and BPH are defined as the central positions in the V and H directions of the beam cross-section at the focus position. The center position may be, for example, the center position of the light intensity distribution in each of the V and H directions, or the center position of each of the spot diameters _DCV and _DCH .

2.2 Operation 2.2.1 Main Flow FIG. 6 is a flow chart showing the laser processing method according to the first embodiment. The step-and-repeat laser processing is performed by the laser processing processor 53 controlling the laser processing device 5a as follows.
In S90, the laser processing processor 53 shifts the position of the workpiece SUB in the X direction and the Control in the Y direction.

At S100, the laser processing processor 53 calculates various control parameters. Details of S100 will be described later with reference to FIG.

At S110, the laser processing processor 53 closes the shutter 59, transmits a trigger signal to the laser device 1, and starts adjusted oscillation.

In S120, the laser processing processor 53 feedback-controls the beam divergence BDV and BDH and the beam pointing BPV and BPH. In FIG. 6, beam divergence and beam pointing may be abbreviated as BD and BP, respectively. Details of S120 will be described later with reference to FIG.

At S130, the laser processing processor 53 determines whether the beam divergence BDV and BDH and the beam pointing BPV and BPH are OK. This determination is made based on the result of the process of S120 shown in FIG.

If the beam divergence BDV and BDH and the beam pointing BPV and BPH are OK (S130: YES), the laser processing processor 53 proceeds to S140. If not OK (S130: NO), the laser processing processor 53 returns the process to S120.

At S140, the laser processing processor 53 ends the adjustment oscillation and opens the shutter 59. In this way, the pulsed laser beam Out is blocked until the measurement results of the beam divergence BDV and BDH and the beam pointing BPV and BPH are within the allowable range.

In S160, the laser processing processor 53 controls the position of the workpiece SUB in the Z direction so that the workpiece SUB is positioned on the focal plane of the condensing optical system 67.

At S170, the laser processing processor 53 starts irradiating the current processing area with the pulsed laser beam Out.

In S180, the laser processing processor 53 feedback-controls the beam divergence BDV and BDH and the beam pointing BPV and BPH. The processing of S180 is the same as the processing of S120, and details thereof will be described later with reference to FIG.

In S190, the laser processing processor 53 irradiates the current processing area with the pulse laser beam Out of the irradiation pulse number n determined in S100, and then terminates irradiation of the current processing area with the pulse laser beam Out.

In S200, the laser processing processor 53 determines whether the beam divergence BDV and BDH and the beam pointing BPV and BPH are OK.
If the beam divergence BDV and BDH and the beam pointing BPV and BPH are OK (S200: YES), the laser processing processor 53 proceeds to S210. If not OK (S200: NO), the laser processing processor 53 returns the process to S110.

At S210, the laser processing processor 53 determines whether or not irradiation of all processing areas of the workpiece SUB has been completed. When the irradiation of all the processing areas is completed (S210: YES), the laser processing processor 53 ends the processing of this flowchart. If unprocessed areas remain (S210: NO), the laser processing processor 53 proceeds to S220.

In S220, the laser processing processor 53 controls the position of the workpiece SUB in the X and Y directions so that the next processing area is processed with the pulse laser beam Out. After S220, the laser processing processor 53 returns the process to S160.

2.2.2 Calculation of Control Parameters FIG. 7 is a flowchart showing the details of the process of calculating control parameters. The processing shown in FIG. 7 corresponds to the subroutine of S100 shown in FIG.

At S101, the laser processing processor 53 reads the target spot diameter Dt on the workpiece SUB from the memory 53a. The target spot diameter Dt is a target value for the spot diameter in the V direction and the spot diameter in the H direction. Here, the case where the same target spot diameter Dt is used in the V direction and the H direction will be described, but different target spot diameters may be used.

At S102, the laser processing processor 53 reads the target fluence Ft from the memory 53a. The fluence is the energy density of the pulsed laser beam Out on the surface of the workpiece SUB.

In S103, the laser processing processor 53 reads the irradiation pulse number n and repetition frequency Rf in one processing area from the memory 53a. In S101 to S103, various data are read from the memory 53a, but data received from a computer device (not shown) may be read, or data input by an operator may be read.

In S104, the laser processing processor 53 calculates the target divergence BDt by the following formula.
BDt=Dt/f ₆₇
Target divergence BDt is the target value of beam divergence BDV and BDH. Although the same target value is set for the V direction and the H direction here, different target values may be set. However, the beam divergence BDV and BDH in the V direction and the H direction of the pulsed laser beam Out that has passed through the divergence adjuster 54 are larger than the difference in the beam divergence in the V direction and the H direction of the pulsed laser beam Out entering the divergence adjuster 54 . It is desirable that the difference between the target values of is small. The beam divergence in the V direction and the H direction of the pulsed laser beam Out entering the divergence adjuster 54 corresponds to the third and fourth beam divergence in the present disclosure.

In S105, the laser processing processor 53 calculates the target pulse energy Et by the following formula.
Et = Ft P S/T
Here, P is the number of machining points in one machining area. S is the area of the beam cross section of one processing point at the focal position of the condensing optical system 67, and is given by the following formula using the target spot diameter Dt.
S=π(Dt/2) ²
T is the transmittance of the optical system in the laser processing device 5a and is given by the following equation.
T=Ta・To
Here, Ta is the transmittance of the attenuator 52 and To is the transmittance of the optical elements other than the attenuator 52 .

After S105, the laser processing processor 53 ends the processing of this flowchart and returns to the processing shown in FIG.

2.2.3 Feedback Control of Beam Divergence BDV and BDH and Beam Pointing BPV and BPH FIG. 8 is a flow chart showing details of processing for feedback control of beam divergence BDV and BDH and beam pointing BPV and BPH. The processing shown in FIG. 8 corresponds to the subroutines of S120 and S180 shown in FIG.

In S121, the laser processing processor 53 measures the beam divergence BDV and BDH in the V direction and the H direction and the beam pointing BPV and BPH in the V direction and the H direction using the measuring instrument 55.

In S122, the laser processing processor 53 calculates differences ΔBDV, ΔBDH, ΔBPV, and ΔBPH between the beam divergence BDV and BDH and the beam pointing BPV and BPH and their target values using the following equations.
ΔBDV = BDV - BDt
ΔBDH = BDH - BDt
ΔBPV=BPV-BPVt
ΔBPH = BPH - BPHt
BPVt and BPHt are target values for beam pointing BPV and BPH, respectively.

At S123, the laser processing processor 53 determines whether the differences ΔBDV, ΔBDH, ΔBPV, and ΔBPH are equal to or less than their respective thresholds. If all of the differences ΔBDV, ΔBDH, ΔBPV, and ΔBPH are equal to or less than their respective threshold values (S123: YES), the laser processing processor 53 proceeds to S124. If any of the differences ΔBDV, ΔBDH, ΔBPV, and ΔBPH exceeds the threshold (S123: NO), the laser processing processor 53 proceeds to S125.

In S124, the laser processing processor 53 stores in the memory 53a a flag indicating that the beam divergence BDV and BDH and the beam pointing BPV and BPH are OK.
In S125, the laser processing processor 53 stores in the memory 53a a flag indicating that one of the beam divergence BDV and BDH and the beam pointing BPV and BPH is NG.
In S130 and S200 shown in FIG. 6, these flags are read out and determined.

After S124 or S125, in S126, the laser processing processor 53 controls the divergence adjuster 54 and the beam steering device so that the differences ΔBDV, ΔBDH, ΔBPV, and ΔBPH approach zero.
After S126, the laser processing processor 53 ends the processing of this flowchart and returns to the processing shown in FIG.

2.3 Action (1) According to the first embodiment, the laser processing system measures the beam divergence BDV in the V direction and the beam divergence BDH in the H direction of the pulsed laser beam Out output from the laser device 1. It includes a divergence adjuster 54 to adjust. The beam divergence BDV and BDH of the pulsed laser beam Out that has passed through the divergence adjuster 54 is measured by the measuring device 55 . The laser processing processor 53 controls the divergence adjuster 54 based on the measurement result by the measuring device 55 so that the beam divergence BDV and BDH approach their respective target values. The pulsed laser beam Out that has passed through the measuring device 55 is branched by the diffraction optical element 63 . According to this, the cross-sectional shape of the branched light that is branched by the diffractive optical element 63 and enters the workpiece SUB can be brought closer to a desired shape.
Further, even when the beam divergence of the pulsed laser beam Out output from the laser device 1 changes due to changes in the temperature of the optical elements included in the laser device 1 or wear of the

discharge electrodes

11a and 11b, the diffraction optics The beam divergence BDV and BDH of the pulsed laser beam Out entering the element 63 is stabilized by the divergence adjuster 54 . As a result, the cross-sectional shape of the branched light irradiated to the workpiece SUB is stabilized, and the shape of the hole machined in the workpiece SUB is stabilized.

(2) According to the first embodiment, the difference in the beam divergence in the V direction and the H direction of the pulsed laser beam Out entering the divergence adjuster 54 is greater than the V of the pulsed laser beam Out that has passed through the divergence adjuster 54 The difference between target values of beam divergence BDV and BDH in the direction and H direction is small. According to this, the dimensional difference between the long side and the short side in the cross-sectional shape of the branched light irradiated to the workpiece SUB is reduced.
FIG. 9 shows a cross section of the branched light Out2 of the pulsed laser light Out incident on the workpiece SUB in the first embodiment. When the same target spot diameter Dt is set in the V direction and the H direction, the cross-sectional shape of the branched light Out2 that irradiates the workpiece SUB becomes nearly circular. As a result, the shape of the hole machined in the workpiece SUB may become nearly circular.

(3) According to the first embodiment, the laser processing system further includes a beam steering device that adjusts the traveling direction of the pulsed laser beam Out. The beam steering device is composed of an actuator 51 d and a high reflection mirror 51 c and is arranged in the optical path of the pulsed laser beam Out between the laser device 1 and the diffractive optical element 63 . The beam pointing BPV and BPH of the pulsed laser beam Out that has passed through the beam steering device are measured by the measuring instrument 55 . The laser processing processor 53 controls the beam steering device based on the measurement result by the measuring instrument 55 so that the beam pointing BPV and BPH approach target values. According to this, a desired position of the workpiece SUB can be irradiated with the branched light Out2. Further, even when the beam pointing of the pulse laser beam Out output from the laser device 1 changes due to changes in the temperature of the optical elements included in the laser device 1 or wear of the

discharge electrodes

11a and 11b, the diffraction optics The beam pointings BPV and BPH of the pulsed laser light Out entering the element 63 are stabilized by the beam steering device. As a result, the position of the branched light Out2 irradiated to the workpiece SUB is stabilized, and the position of the hole machined in the workpiece SUB is stabilized.

(4) According to the first embodiment, the laser processing system further includes the shutter 59 capable of switching between passage and blocking of the pulsed laser beam Out. The shutter 59 is arranged on the optical path of the pulsed laser beam Out that has passed through the measuring instrument 55 . The laser processing processor 53 controls the shutter 59 so that the pulsed laser beam Out is blocked until the measurement results of the beam divergence BDV and BDH by the measuring device 55 are within respective allowable ranges including respective target values. According to this, since the workpiece SUB is machined after the measurement result falls within the allowable range, high machining accuracy can be obtained.

(5) According to the first embodiment, the laser processing system further includes a condensing optical system 67 arranged on the optical path of the pulsed laser beam Out that has passed through the diffractive optical element 63 . Workpiece SUB is positioned at the focal plane of condensing optics 67 . According to this, the branched light beams branched by the diffractive optical element 63 can be collected to perform fine processing.

(6) According to the first embodiment, the laser device 1 included in the laser processing system includes an optical resonator housed in the first housing 100 . The divergence adjuster 54 and the diffractive optical element 63 are housed in the second housing 500 . According to this, since the beam divergence BDV and BDH are adjusted in the laser processing device 5a, even if the beam divergence of the pulsed laser beam Out output from the laser device 1 changes, the branched light irradiated to the workpiece SUB can be stabilized.
Otherwise, the first embodiment is the same as the comparative example.

2.4 Laser processing system in which laser device 1b includes divergence adjuster 20 2.4.1 Configuration FIG. 10 schematically shows the configuration of a laser processing system in a modification. In FIG. 10, a divergence adjuster 20 and a measuring device 21 are included in the laser device 1b, and these components are accommodated in the first housing 100 together with the optical resonator. The laser processing device 5b may not include the divergence adjuster 54.

The configuration of the divergence adjuster 20 is similar to the configuration of the divergence adjuster 54, and will be described later with reference to FIGS. 15-26.

Measuring instrument 21 includes beam splitter 22 , convex lens 23 , and image sensor 24 . The beam splitter 22 is positioned on the optical path of the pulsed laser beam Out that has passed through the divergence adjuster 20 . The convex lens 23 is positioned on the optical path of the pulsed laser beam Out reflected by the beam splitter 22 . The convex lens 23 has a focal length _f23 . Focal length f ₂₃ may be greater than focal length f ₆₇ of collection optics 67 . The image sensor 24 is positioned on the focal plane of the convex lens 23 on the optical path of the pulsed laser beam Out that has passed through the convex lens 23 . Here, the convex lens 23 may be a combined lens having a focal length of _f23 , which is a combination of a concave lens and a convex lens. The measuring instrument 21 is configured to be able to measure beam divergence BDV and BDH.

2.4.2 Operation The laser control processor 13 feedback-controls the divergence controller 20 based on the beam divergence BDV and BDH measured by the measuring device 21 and the calculated target divergence BDt.

The laser processing processor 53 feedback-controls the actuator 51d based on the beam pointing BPV and BPH measured by the measuring instrument 55 and the target values BPVt and BPHt of the beam pointing BPV and BPH obtained by calculation.

Thus, in the modified example, the beam divergence BDV and BDH are measured and controlled in the laser device 1b, and the beam pointing BPV and BPH are measured and controlled in the laser processing device 5b. 9 differs from that described with reference to FIG. Other points may be the same as those described with reference to FIGS.

Since the beam divergence BDV and BDH can also be measured by the measuring device 55, laser processing may be performed while confirming that the beam divergence BDV and BDH measured by the measuring device 55 are OK. Adjustment oscillation may be performed when any one of the beam divergence BDV and BDH measured by the measuring device 55 is NG.

As yet another modified example, the measuring device 21 may be removed from the configuration of FIG. The divergence adjuster 20 may be controlled based on the beam divergence BDV and BDH measured by the measuring device 55 .

2.4.3 Action (7) According to the modification, the laser device 1b included in the laser processing system includes the optical resonator and the divergence adjuster 20 housed in the first housing 100. FIG. The diffractive optical element 63 is housed in the second housing 500 . According to this, the pulsed laser beam Out whose beam divergence BDV and BDH are adjusted is output from the laser device 1b, so that the configuration of the laser processing device 5b can be suppressed from being complicated.
Otherwise, the variant is similar to that described with reference to FIGS. 4-9.

3. A laser processing system in which a mask 65 is placed in the optical path of the branched light by the diffractive optical element 63 and the image of the mask 65 is transferred to the workpiece SUB 3.1 Configuration and Operation FIG. 11 shows a laser processing system according to the second embodiment. schematically shows the configuration of In the second embodiment, the laser processing apparatus 5c included in the laser processing system includes a condensing optical system 64 instead of the condensing optical system 67 shown in FIG. 68 and .

The condensing optical system 64 is arranged inside the second housing 500 on the optical path of the pulsed laser beam Out that has passed through the diffractive optical element 63, and has a focal length _f64 . In other respects, the condensing optical system 64 is similar to the condensing optical system 67 described with reference to FIG.

The mask 65 is positioned on the focal plane of the condensing optical system 64 on the optical path of the pulsed laser beam Out that has passed through the condensing optical system 64 .
FIG. 12 is a plan view of the mask 65 in the second embodiment. Mask 65 has a number of circular openings M1, each having a diameter of Dm. Each opening M1 is desirably circular. The branched beams of the pulsed laser beam Out branched by the diffractive optical element 63 pass through the condensing optical system 64, so that the cross section _S65 of the branched beams at the position of the mask 65 overlaps with the position of the aperture M1. Each is condensed. The alignment of the cross-section S ₆₅ of the split light and the aperture M1 is adjusted by a beam steering device. The diameter of each branched light cross section S ₆₅ is adjusted by the divergence adjuster 54 so as to approach the target spot diameter Dt. The target spot diameter Dt is set so as to satisfy Equation 1 below.
Dm≦Dt≦K Dm Formula 1
Here, K is preferably 1.1 or more and 1.4 or less.

Referring again to FIG. 11, the projection optical system 68 is positioned on the optical path of the pulsed laser beam Out that has passed through the mask 65, and includes first and

second lenses

68a and 68b. The second lens 68b also serves as a window of the second housing 500. FIG. A projection optical system 68 projects the image of the mask 65 onto the workpiece SUB. The beam diameter of each of the branched lights on the workpiece SUB is obtained by multiplying the diameter Dm of each of the apertures M1 of the mask 65 by the magnification of the projection optical system 68. FIG.

3.2 Action (8) According to the second embodiment, the laser processing system includes a condensing optical system 64 arranged in the optical path of the pulsed laser beam Out that has passed through the diffractive optical element 63, and a condensing optical system 64 and includes a mask 65 having a plurality of apertures, and a projection optical system 68 arranged in the optical path of the pulsed laser beam Out that has passed through the mask 65 . According to this, the image of the mask 65 can be projected onto the workpiece SUB by the projection optical system 68, and the cross-sectional shape of the branched light of the pulse laser beam Out irradiated onto the workpiece SUB can be approximated to a desired shape. be able to. Further, according to the second embodiment, by making the shape of the opening M1 of the mask 65 a perfect circle, the cross-sectional shape of the branched light of the pulse laser beam Out irradiated to the workpiece SUV is the same as that of the first embodiment. The shape can be closer to a perfect circle than the form.

(9) According to the second embodiment, the light condensing system 64 divides the branched light beams so that the cross sections of the plurality of branched beams of the pulsed laser beam Out branched by the diffractive optical element 63 overlap the plurality of apertures M1. converge respectively. According to this, since each of the branched lights split by the diffractive optical element 63 is condensed at the position of the aperture M1 of the mask 65 by the condensing optical system 64, the loss of light in the mask 65 is reduced, and the light is utilized. Efficiency can be improved.
Further, by controlling the beam divergence BDV and BDH of the pulsed laser beam Out incident on the diffractive optical element 63 , each of the branched beams split by the diffractive optical element 63 is converged on the mask 65 by the condensing optical system 64 . The shape of the spot can be made close to the shape of the opening M1 of the mask 65, and the light utilization efficiency can be improved.
Further, by controlling the beam pointing BPV and BPH of the pulsed laser beam Out incident on the diffractive optical element 63, the position of the branched beam incident on the mask 65 can be stabilized and the light utilization efficiency can be improved.
Otherwise, the second embodiment is similar to the first embodiment.

4. Laser Processing System for Making Light Passing Through Mask 61 Enter Diffractive Optical Element 63 4.1 Configuration and Operation FIG. 13 schematically shows the configuration of a laser processing system according to the third embodiment. In the third embodiment, a laser processing device 5d included in the laser processing system includes a condenser lens 60, a mask 61, and a collimator optical system 62 in addition to the components shown in FIG.

The condenser lens 60 is positioned in the optical path of the pulsed laser beam Out between the shutter 59 and the diffractive optical element 63, and has a focal length _f60 . The condensing lens 60 is not limited to one lens, and may include a plurality of lenses.

The mask 61 is positioned on the optical path of the pulsed laser beam Out that has passed through the condenser lens 60 and at the focal point of the condenser lens 60 .
FIG. 14 is a plan view of mask 61 in the third embodiment. The mask 61 has one circular opening M2, and the diameter of the opening M2 is Dm. The aperture M2 is preferably circular. The pulsed laser beam Out is condensed at the position of the mask 61 by the condensing lens 60 . The beam steering device is controlled such that the cross section _S61 of the pulsed laser beam Out on the mask 61 matches the position of the aperture M2. The divergence adjuster 54 is controlled so that the diameter of the cross section _S61 approaches the target spot diameter Dt. The target spot diameter Dt is set so as to satisfy Equation 1 above.

Referring to FIG. 13 again, when the pulsed laser beam Out is focused on the opening of the mask 61, plasma may be generated at the opening of the mask 61 and break down if the mask 61 is in the air. . Therefore, the mask 61 may be placed inside a vacuum chamber 61a having windows between the condenser lens 60 and the collimator optics 62, respectively.
In addition, a refrigerant jacket (not shown) may be attached to the mask 61 in order to prevent the mask 61 from becoming hot. Also, as the material of the mask 61, a high melting point metal such as tungsten or molybdenum may be used.

The collimator optical system 62 is positioned on the optical path of the pulsed laser beam Out that has passed through the mask 61 . The collimator optical system 62 has a focal length f ₆₂ and the mask 61 is positioned at the front focal point of the collimator optical system 62 . The collimator optical system 62 emits the pulsed laser beam Out that has passed through the aperture M2 of the mask 61 as parallel light, and makes it enter the diffractive optical element 63 . The collimator optical system 62, the diffractive optical element 63, and the condensing optical system 67 project the image of the mask 61 onto a plurality of positions on the workpiece SUB. The beam diameter of each of the branched lights on the workpiece SUB is the diameter Dm of the aperture M2 of the mask 61, the projection optical system composed of the collimator optical system 62, the diffractive optical element 63, and the condensing optical system 67. Multiplied by the magnification.

4.2 Action (10) According to the third embodiment, the laser processing system is arranged in the optical path of the pulsed laser beam Out that has passed through the measuring instrument 55, and includes the condenser lens 60 that collects the pulsed laser beam Out. , a mask 61 arranged on the optical path of the pulsed laser beam Out that has passed through the condenser lens 60, and a collimator optical system 62 arranged on the optical path of the pulsed laser beam Out between the mask 61 and the diffractive optical element 63. include. According to this, the pulsed laser beam Out that has passed through the condenser lens 60 can be focused on the opening M2 of the mask 61, so alignment of the focusing position of the pulsed laser beam Out is facilitated.

(11) According to the third embodiment, the mask 61 is positioned at the focal point of the condenser lens 60 . This makes it easier to align the mask 61 and the condenser lens 60 .

(12) According to the third embodiment, the laser processing system includes the condensing optical system 67 arranged in the optical path of the pulsed laser beam Out that has passed through the diffractive optical element 63, and the collimator optical system 62 and the diffractive optical element The image of the mask 61 is projected onto a plurality of positions on the workpiece SUB by the 63 and the condensing optical system 67 . According to this, the image of the mask 61 is projected onto the workpiece SUB, so that the cross-sectional shape of the branched light of the pulse laser beam Out irradiated onto the workpiece SUB can be approximated to a desired shape. Further, according to the third embodiment, by making the shape of the opening M2 of the mask 61 a perfect circle, the cross-sectional shape of the branched light of the pulse laser beam Out irradiated to the workpiece SUV is the same as that of the first embodiment. The shape can be closer to a perfect circle than the form.

5. Details of Divergence Adjuster Details of the divergence adjuster will now be described with reference to FIGS. Each of the divergence adjusters described below can be used as the divergence adjuster 54 described with reference to FIGS. 4, 11, or 13 or as the divergence adjuster 20 described with reference to FIG.

5.1 Divergence adjuster 541 for adjusting the beam divergence angle
5.1.1 Configuration and Operation Figures 15 and 16 schematically show a first example of a divergence adjuster. 15 is a view of the divergence adjuster 541 viewed in the -V direction, and FIG. 16 is a view viewed in the -H direction.

In the first example, the divergence adjuster 541 includes two sets of cylindrical lenses. The two sets of cylindrical lenses include one set of concave lens 541a and convex lens 541b and one set of concave lens 541c and convex lens 541d.

The

concave lenses

541a and 541c are fixed by

holders

541e and 541g, respectively.

Convex lenses

541b and 541d are supported by

holders

541f and 541h, respectively. The

holders

541f and 541h include

protrusions

541n and 541o, respectively, and are movable parallel to the L direction by

linear stages

541i and 541j, respectively.

A linear stage 541i includes a plunger 541k and a micrometer 541p. A protrusion 541n of the holder 541f is sandwiched between the plunger 541k and the micrometer 541p. The plunger 541k incorporates a spring (not shown). The micrometer 541p is configured such that the tip portion contacting the protrusion 541n expands and contracts in parallel with the L direction in response to a control signal from the laser processing processor 53 or the laser control processor 13 . As the tip of the micrometer 541p expands and contracts, the protrusion 541n of the holder 541f is pressed by the plunger 541k or the micrometer 541p, and the holder 541f moves in the arrow A1 direction together with the convex lens 541b.

A linear stage 541j includes a plunger 541m and a micrometer 541q. The configuration for the linear stage 541j to move the convex lens 541d in the arrow A2 direction is similar to that of the linear stage 541i.

The concave lens 541a and the convex lens 541b each have a focal axis parallel to the H direction. When these focal axes coincide, the concave lens 541a and the convex lens 541b transmit the pulse laser beam Out without changing the beam divergence angle in the V direction as indicated by the dashed line in FIG. When the convex lens 541b is moved in the direction of the arrow A1, the beam divergence angle in the V direction is adjusted to the positive direction as indicated by the one-dot chain line in FIG. It can be adjusted in the negative direction.

The concave lens 541c and the convex lens 541d each have a focal axis parallel to the V direction. When these focal axes coincide, the concave lens 541c and the convex lens 541d transmit the pulse laser beam Out without changing the beam divergence angle in the H direction, as indicated by the dashed line in FIG. When the convex lens 541d is moved in the direction of the arrow A2, the beam divergence angle in the H direction is adjusted to the positive direction as indicated by the one-dot chain line in FIG. It can be adjusted in the negative direction.

5.1.2 Action (13) According to the first example, the divergence adjuster 541 is configured to adjust the beam divergence angles in the V and H directions. According to this, the beam divergence BDV and BDH in the V direction and the H direction can be controlled independently of each other.

FIG. 17 shows the principle by which the beam divergence BDV and BDH are adjusted in the first example. FIG. 17 shows how the pulsed laser beam Out that has passed through the divergence adjuster 541 is transmitted through the convex lens 57 included in the measuring device 55 and condensed. As indicated by the dashed line in FIG. 17, when the pulsed laser beam Out that has passed through the divergence adjuster 541 is parallel light, the position F at a focal distance _f57 from the convex lens 57 is the narrowest beam waist position. Become. On the other hand, as shown by the dashed line in FIG. 17, when the pulsed laser beam Out that has passed through the divergence adjuster 541 has a positive divergence angle, the position W farther than the focal length _f57 from the convex lens 57 is the beam is the narrowest beam waist position. By changing the divergence angle of the pulsed laser beam Out in this way, the beam waist position is shifted, and as a result, the beam width at the focal point position F is changed, and the beam divergence BDV and BDH can be adjusted.

When adjusting the beam divergence BDV and BDH in the first example, the minimum value of the beam divergence BDV and BDH depends on the beam width _DW at the beam waist position W. The beam width _DW at the beam waist position W is given by Equation 2 below.
D _W =(4/π)λM ² /NA={(8/π)(F _W / _DL )}·λM ² Equation 2
Here, λ is the wavelength of the pulsed laser beam Out, M ² is the M square value of the pulsed laser beam Out, and NA is the numerical aperture of the convex lens 57 . _FW is the distance from the convex lens 57 to the beam waist position W, and _DL is the beam diameter given by the full width of the beam cross section of the pulsed laser beam Out incident on the convex lens 57 . Note that the numerical aperture NA is given by (1/2) _DL / _FW .

As can be seen from Equation 2, the beam width _DW , which is the full width of the beam cross section at the beam waist position W, is proportional to the M square value of the pulsed laser beam Out and proportional to _FW / _DL .
In order to widen the adjustment range of the beam divergence BDV and BDH in the first example, for example, the beam width _DW at the beam waist position W can be reduced by reducing the M square value of the pulsed laser beam Out. It is valid. The beam divergence BDV and BDH can be minimized by adjusting the divergence angle of the pulsed laser beam Out and bringing the beam waist position W closer to the focus position F.

5.2 Divergence adjuster 542 for adjusting beam width
5.2.1 Configuration and Operation Figures 18 and 19 schematically show a second example of a divergence adjuster. 18 is a view of the divergence adjuster 542 in the -V direction, and FIG. 19 is a view in the -H direction.

In a second example, divergence adjuster 542 includes two beam expanders. For example, one of the two beam expanders consists of a pair of

similar prisms

542a and 542b and the other consists of a pair of

similar prisms

542c and 542d.

Each of the

prisms

542a and 542b constituting one beam expander receives the pulsed laser beam Out from one side surface parallel to the V direction and emits the pulsed laser beam Out from the other side surface parallel to the V direction. The

prisms

542a and 542b are configured to be rotatable about axes parallel to the V direction by

rotary stages

542e and 542f, respectively. As shown in FIG. 18, by rotating the

prisms

542a and 542b in opposite directions so that the angles of incidence of the pulsed laser beam Out on the

prisms

542a and 542b are equal, the beam of the pulsed laser beam Out passing through the beam expander in the H direction is Width can be adjusted.

Each of the

prisms

542c and 542d constituting the other beam expander receives the pulsed laser beam Out from one side surface parallel to the H direction and emits the pulsed laser beam Out from the other side surface parallel to the H direction. The

prisms

542c and 542d are configured to be rotatable around axes parallel to the H direction by

rotary stages

542g and 542h, respectively. As shown in FIG. 19, by rotating the

prisms

542c and 542d in opposite directions so that the angles of incidence of the pulsed laser beam Out on the

prisms

542c and 542d are equal, the V-direction beam of the pulsed laser beam Out passing through the beam expander is expanded. Width can be adjusted.

Each of the two beam expanders is not limited to being composed of two prisms, and may be composed of a zoom lens. A zoom lens may be configured by a combination of three or more cylindrical lenses. One zoom lens may adjust the beam width in the V direction and another zoom lens may adjust the beam width in the H direction.

5.2.2 Operation (14) According to the second example, the divergence adjuster 542 is configured to adjust the beam widths in the V and H directions. Also in this example, the beam divergence BDV and BDH in the V and H directions can be controlled independently of each other.

FIG. 20 shows the principle by which the beam divergence BDV and BDH are adjusted in the second example. FIG. 20 shows how the pulsed laser beam Out that has passed through the divergence adjuster 542 is transmitted through the convex lens 57 included in the measuring device 55 and condensed. As shown in FIG. 20, when the divergence adjuster 542 changes the beam width without changing the divergence angle of the pulsed laser beam Out, the beam waist position and the M-square value do not change. Since the beam diameter D _L of the incident pulsed laser beam Out changes, F _W /D _L shown in Equation 2 changes. Thereby, the beam width _DW at the beam waist position W can be changed to adjust the beam divergence BDV and BDH. Although FIG. 20 shows the case where the beam waist position W coincides with the focal position F of the convex lens 57, the beam diameter D of the pulsed laser beam Out incident on the convex lens 57 can be changed even if the beam waist position W is not the same. By changing _L , the beam width at position F can be changed.

5.3 Divergence adjuster 543 for once condensing and fine-tuning with a slit
5.3.1 Configuration and Operation Figures 21 and 22 schematically show a third example of a divergence adjuster. 21 is a view of the divergence adjuster 543 in the -V direction, and FIG. 22 is a view in the -H direction.
In the third example, the divergence adjuster 543 includes a variable slit 543a, first and second cylindrical

convex lenses

543d and 543b, and a collimator lens 543e. The positional relationship of these optical elements may be fixed with respect to each other.

The opening width of the variable slit 543a in the V direction is adjusted by an actuator 543f, and the opening width in the H direction is adjusted by an actuator 543g. The variable slit 543a passes portions of the pulsed laser beam Out incident on the divergence adjuster 543 corresponding to the respective aperture widths in the V and H directions, and cuts off portions exceeding these aperture widths. It is possible to adjust the beam width in each of the direction and the H direction. The variable slit 543a may be able to adjust the beam width in either the V direction or the H direction.

The first and second cylindrical

convex lenses

543d and 543b are arranged on the optical path of the pulsed laser beam Out that has passed through the variable slit 543a. The back focal axis of the first cylindrical convex lens 543d is parallel to the H direction and positioned at the front focal position F of the collimator lens 543e. The back focal axis of the second cylindrical convex lens 543b is parallel to the V direction and positioned at the front focal point F of the collimator lens 543e. Thereby, the first and second cylindrical

convex lenses

543d and 543b converge the pulse laser beam Out in the V direction and the H direction, respectively.

In the excimer laser device, since the M square value in the V direction is larger than the M square value in the H direction, the focal length f _543d of the first cylindrical convex lens 543d is set longer than the focal length f 543b of the second cylindrical convex lens _543b . By reducing the size, the beam diameter in the V direction and the beam diameter in the H direction at the position F can be brought closer.

The collimator lens 543e is positioned on the optical path of the pulsed laser beam Out that has passed through the first and second cylindrical

convex lenses

543d and 543b. Collimator lens 543e has a focal length f _543e . The collimator lens 543e may be composed of a spherical convex lens, or may be composed of a double-sided cylindrical convex lens having a focal axis in the V direction and a focal axis in the H direction. Also, the configuration is not limited to one lens, and may include a plurality of lenses. Thereby, the collimator lens 543e collimates the pulsed laser beam Out condensed by the first and second cylindrical

convex lenses

543d and 543b.

5.3.2 Action (15) According to the third example, the divergence adjuster 543 includes first and second cylindrical

convex lenses

543d and 543b that converge the pulsed laser beam Out in the V direction and the H direction, respectively. , and a collimator lens 543e for collimating the pulsed laser beam Out condensed by the first and second cylindrical

convex lenses

543d and 543b. According to this, the beam cross section on the workpiece SUB becomes a transfer image of the beam cross section at the position F of the front focal point of the collimator lens 543e. Therefore, by using the first and second cylindrical

convex lenses

543d and 543b to approximate the beam cross section at the position F to a perfect circle, the beam cross section at the workpiece SUB can be approximated to a perfect circle.

When the V-direction and H-direction M square values of the pulsed laser beam Out incident on the divergence adjuster 543 are known in advance, the beam diameter in the V direction and the beam diameter in the H direction at the focus position F are the same. It is desirable to determine the focal lengths f 1 543d and f _543b of the first and second cylindrical convex lenses _543d and 543b as follows. Specifically, it is calculated as follows.

Assume that the beam waist position W coincides with the focal point position F in the configuration shown in FIGS. In Equation 2, if the beam width _DW at the beam waist position W is replaced by the target spot diameter Dt, and the distance FW to the beam waist position _W is replaced by the focal length ft of the cylindrical convex lens, the focal length ft of the cylindrical convex lens is: calculated by the formula.
ft=π·Dt· _DL /(λM ² )

More specifically, let D _LV be the beam diameter in the V direction of the pulsed laser beam Out incident on the divergence adjuster 543, and let M ² _V be the M square value in the V direction _. is obtained by the following formula 3.
_ftV =π*Dt* _DLV / ₍ ^λM2V ) Equation 3
Assuming that the beam diameter in the H direction of the pulsed laser beam Out incident on the divergence adjuster 543 is _DLH , and the M square value in the H direction is M ² _H , the focal length _ftH of the second cylindrical convex lens 543b is expressed by the following equation. 4.
ft _H = π·Dt·D _LH /(λM ² _H ) Equation 4

(16) According to the third example, the divergence adjuster 543 blocks part of the pulsed laser beam Out entering the first and second cylindrical

convex lenses

543d and 543b to A variable slit 543a is included to adjust the beam width in either direction. Thereby, the shape of the beam cross section in the workpiece SUB can be finely adjusted.

5.4 Divergence adjuster 544 for once condensing and fine adjustment with lens position
5.4.1 Configuration and Operation Figures 23 and 24 schematically show a fourth example of a divergence adjuster. 23 is a view of the divergence adjuster 544 in the -V direction, and FIG. 24 is a view in the -H direction.

In the fourth example, divergence adjuster 544 does not include variable slit 543a, and first and second cylindrical

convex lenses

544d and 544b are movable parallel to the L direction by

linear stages

544j and 544i, respectively. It differs from the third example in that For other points, the description regarding the first and second cylindrical

convex lenses

543d and 543b and the collimator lens 543e in the third example is the same as the first and second cylindrical

convex lenses

544d and 544b and the collimator lens in the fourth example. The description of lens 544e also applies.

The configuration for moving the first and second cylindrical

convex lenses

544d and 544b by the

linear stages

544j and 544i is the same as the configuration for moving the cylindrical

convex lenses

541d and 541b in the first example. Linear stages 544j and 544i correspond to first and second linear stages, respectively, in this disclosure.

5.4.2 Action (17) According to the fourth example, the divergence adjuster 544 is a linear stage that moves the first and second cylindrical

convex lenses

544d and 544b along the traveling direction of the pulse laser beam Out. 544j and 544i. According to this, by changing the beam waist position inside the divergence adjuster 544 and changing the beam cross section at the focal point position F, the shape of the beam cross section on the workpiece SUB can be finely adjusted.
In the fourth example, a variable slit 543a similar to the third example may be further provided, and fine adjustment by the variable slit 543a may be added.

5.5 Divergence adjuster 545 containing an optical pulse stretcher misaligned in the H direction
5.5.1 Configuration and Operation FIG. 25 schematically shows a fifth example of a divergence adjuster. In the fifth example, the divergence adjuster 545 is composed of an optical pulse stretcher that branches the optical path of the pulsed laser beam Out. The optical pulse stretcher includes beam splitter 545a, concave mirrors 545b-545e, and actuator 545f.

The beam splitter 545a is arranged in the optical path of the pulsed laser beam Out entering the divergence adjuster 545 as the beam B11. The reflectivity of the beam splitter 545a is, for example, 60%.
Concave mirrors 545b, 545c, 545d, and 545e are spherical mirrors and are arranged in this order in the optical path of the beam B21 reflected by the beam splitter 545a. The concave mirrors 545b to 545e form a loop-shaped delay optical path.
The actuator 545f is configured to change the attitude of the concave mirror 545e.

Beam splitter 545a transmits part of beam B11 as beam B12 and reflects another part as beam B21. The concave mirrors 545b to 545e sequentially reflect the beam B21 to enter the beam splitter 545a.
Beam splitter 545a reflects part of beam B21 as beam B22 and transmits another part as beam B31. The concave mirrors 545b to 545e sequentially reflect the beam B31 to enter the beam splitter 545a.
Beam splitter 545a reflects a portion of beam B31 as beam B32.

Thus, beams B12, B22, and B32 are output from the divergence adjuster 545. At this time, the concave mirrors 545b to 545e are intentionally misaligned so that the beams B12, B22, and B32 diverge as beams shifted in the H direction.

The actuator 545f finely adjusts the amount of deviation of the beams B12, B22, and B32 in the H direction by changing the attitude of the concave mirror 545e.
In this manner, the divergence adjuster 545 adjusts the beam divergence BDH in the H direction of the pulsed laser light Out including the beams B12, B22, and B32.

In order to prevent the beams B12, B22, and B32 from interfering with each other, it is desirable to set the optical path length of the delay optical path composed of the concave mirrors 545b to 545e longer than the temporal coherence length of the pulse laser beam Out.

Further, the concave mirrors 545b to 545e form an image of the beam B11 on the beam splitter 545a as an inverted image as the beam B21 between the

concave mirrors

545c and 545d, and then form an image again when the beam B21 is incident on the beam splitter 545a. It is desirable that the images are arranged so as to form an erect image. Here, if the focal lengths of the concave mirrors 545b to 545e are all the same f ₅₄₅ , the optical path length of the delay optical path is eight times f ₅₄₅ .

5.5.2 Action (18) According to the fifth example, the divergence adjuster 545 includes an optical pulse stretcher configured to branch the optical path of the pulsed laser beam Out in the H direction. According to this, not only can the beam divergence BDH be adjusted, but also the pulse time width can be expanded at the same time.

5.6 Divergence adjuster 546 containing an optical pulse stretcher misaligned in the V direction
FIG. 26 schematically shows a sixth example of a divergence adjuster. In the sixth example, beam splitter 546a, concave mirrors 546b to 546e, and actuator 546f included in divergence adjuster 546 have the same configuration as beam splitter 545a, concave mirrors 545b to 545e, and actuator 545f in the fifth example. have

The difference between the sixth example and the fifth example is as follows.
Concave mirrors 546b-546e are intentionally misaligned so that beams B12, B22, and B32 output from divergence adjuster 546 diverge as beams that are offset from each other in the V direction.

The actuator 546f finely adjusts the amount of deviation of the beams B12, B22, and B32 in the V direction by changing the posture of the concave mirror 546e.
In this manner, the divergence adjuster 546 adjusts the beam divergence BDV in the V direction of the pulsed laser light Out including the beams B12, B22, and B32.
Otherwise, the sixth example is similar to the fifth example.

By arranging the divergence adjuster 545 in the fifth example and the divergence adjuster 546 in the sixth example in the optical path of the pulsed laser beam Out, it is possible to adjust the beam divergence BDV and BDH in both the H direction and the V direction. .

6. Improved Laser Apparatus An improved laser apparatus will now be described with reference to FIGS. 27-30. In order to widen the adjustment range of the beam divergence BDV and BDH, it is desirable to replace the laser device 1 with one of the improved laser devices described below.

6.1 Laser device 1e capable of controlling the attitude of the optical resonator
FIG. 27 schematically shows a first example of an improved laser device. A laser device 1e shown in FIG. 27 includes a measuring device 21 in addition to the configuration of the laser device 1 shown in FIGS. Furthermore, instead of the rear mirror 14, the laser device 1e includes a rear mirror 14e with an actuator 14g. The rear mirror 14e and the output coupling mirror 15 constitute an optical resonator.

The configuration of the measuring instrument 21 is similar to that described with reference to FIG.
The actuator 14g is configured to be able to change the attitude of the rear mirror 14e around axes parallel to each of the V direction and the H direction.

The laser control processor 13 feedback-controls the actuator 14g so that the beam divergence BDV and BDH measured by the measuring instrument 21 are reduced. As a result, even when the temperature of the components of the laser device 1e changes, it is possible to suppress the beam divergence BDV and BDH from increasing due to misalignment of the rear mirror 14e and the output coupling mirror 15. FIG. By using such a laser device 1e, the beam divergence BDV and BDH adjustment range of the divergence adjuster 54 can be widened.

In FIG. 27, the case where the rear mirror 14e is rotatable around the axes parallel to the V direction and the H direction has been described, but instead of the rear mirror 14e, the output coupling mirror 15 is arranged parallel to the V direction and the H direction. rotatable around an axis.

Further, each of the rear mirror 14e and the output coupling mirror 15 may be rotatable around axes parallel to the V direction and the H direction. Thereby, not only the beam divergence BDV and BDH but also the beam pointing BPV and BPH can be adjusted. The measuring instrument 21 can measure both the beam divergence BDV and BDH and the beam pointing BPV and BPH, and the laser control processor 13 controls the beam divergence BDV and BDH and the beam pointing BPV and BPH measured by the measuring instrument 21 to desired values. The postures of the rear mirror 14e and the output coupling mirror 15 may be feedback-controlled so that
The laser device 1e may be the same as the laser device 1 in other respects. Also, the laser device 1e may include a divergence adjuster 20 as in the case of the laser device 1b.

6.2 Laser Device 1f with Unstable Cavity
FIG. 28 schematically shows a second example of an improved laser device. The laser device 1f shown in FIG. 28 includes a concave mirror 14f and a convex mirror 15f that constitute an unstable resonator instead of the rear mirror 14 and the output coupling mirror 15. It differs from the laser device 1 shown in FIG.

The concave mirror 14f and the convex mirror 15f are spherical mirrors and arranged so that their focal positions match. The magnification of these mirrors is, for example, 5 times or more and 10 times or less. The convex mirror 15f is positioned so as to partially block the optical path of the light emitted from the window 10b.

A part of the light emitted from the window 10b of the laser chamber 10 is reflected by the convex mirror 15f, spreads gradually, passes through the discharge space between the

discharge electrodes

11a and 11b, and enters the concave mirror 14f.
The light reflected by the concave mirror 14f passes through the discharge space between the

discharge electrodes

11a and 11b as parallel light. A part of it is output as the pulsed laser beam Out without being incident on the convex mirror 15f.

According to the second example, the number of spatial transverse modes of the pulsed laser beam Out to be output is reduced, and the pulsed laser beam Out close to a single transverse mode can be generated. This makes it possible to reduce the beam divergence BDV and BDH in the V and H directions. By using such a laser device 1f, the adjustment range of the beam divergence BDV and BDH by the divergence adjuster 54 can be widened. Moreover, compared with the case where the laser device 1 is used, a smaller hole can be machined.

The concave mirror 14f and the convex mirror 15f may each be a cylindrical mirror having a focal axis parallel to the H direction. It is desirable that the focal axes of the concave mirror 14f and the convex mirror 15f match. In this case, the concave mirror 14f and the convex mirror 15f are unstable resonators in the V direction and stable resonators in the H direction. As a result, the number of spatial transverse modes in the V direction is reduced, and can be made approximately the same as the number of spatial transverse modes in the H direction, making it possible to reduce the beam divergence BDV in the V direction. Therefore, the adjustment range of the beam divergence BDV in the V direction by the divergence adjuster 54 can be widened. Moreover, compared with the case where the laser device 1 is used, a smaller hole can be machined. Moreover, compared with the case of using a spherical mirror, it is possible to reduce cavity loss and output a pulsed laser beam Out having high energy.

In the second example, as in the first example, the orientation of one or both of the concave mirror 14f and the convex mirror 15f may be controlled.
The laser device 1f may be the same as the laser device 1 in other respects. Also, the laser device 1f may include a divergence adjuster 20 as in the case of the laser device 1b.

6.3 Laser device 1g including amplifier PA
FIG. 29 schematically shows a third example of an improved laser device. The laser device 1g shown in FIG. 29 differs from the laser device 1 shown in FIGS.

The laser chamber 10, power supply device 12, rear mirror 14, and output coupling mirror 15 constitute a master oscillator MO. Amplifier PA includes laser chamber 30 and power supply 32 . The configurations of the laser chamber 30 and power supply 32 may be the same as those of the laser chamber 10 and power supply 12 . The amplifier PA may not contain an optical resonator.

The amplifier PA is configured to amplify the pulsed laser light output from the master oscillator MO. The power supply device is arranged so that the timing at which the pulsed laser light output from the master oscillator MO is incident on the amplifier PA is synchronized with the timing at which the power supply device 32 generates a high voltage to generate a discharge inside the laser chamber 30. The time difference between the trigger signals applied to 12 and 32 respectively is set. The laser control processor 13 feedback-controls the set voltages set in the

power supply devices

12 and 32 based on the pulse energy data measured by the monitor module 16 .

According to the third example, the pulsed laser beam Out having sufficiently high pulse energy for laser processing can be output from the laser device 1g.
In the third example, an unstable resonator similar to that in the second example may be used as the optical resonator included in the master oscillator MO.
In the third example, as in the first example, the attitude of one or both of the rear mirror 14 and the output coupling mirror 15 may be controlled.
The laser device 1g may be the same as the laser device 1 in other respects. Also, the laser device 1g may be provided with a divergence adjuster 20 in the same manner as the laser device 1b.

6.4 Laser Device 1h Including Solid-State Lasers
Figure 30 schematically shows a fourth example of an improved laser device. Laser device 1h shown in FIG. 30 differs from laser device 1g shown in FIG. 29 in that the master oscillator MO includes a solid-state laser.

6.4.1 Configuration The laser device 1 h includes a master oscillator MO, an amplifier PA, and a monitor module 16 . The master oscillator MO contains a solid-state laser and the amplifier PA contains an excimer laser.

The master oscillator MO includes a semiconductor laser 160, a titanium sapphire amplifier 171, a wavelength conversion system 172, a pumping laser 173, and a solid state laser control processor 130.

The semiconductor laser 160 is a distributed feedback semiconductor laser that outputs CW laser light with a wavelength of approximately 773.6 nm, and is configured such that the oscillation wavelength can be changed by changing the set temperature of the semiconductor.

Titanium-sapphire amplifier 171 is an amplifier containing a titanium-sapphire crystal.
The pumping laser 173 is a laser device that outputs the second harmonic of a YLF (yttrium lithium fluoride) laser to excite the titanium sapphire crystal of the titanium sapphire amplifier 171 .

The wavelength conversion system 172 is a system that includes an LBO (lithium triborate) crystal and a KBBF (potassium beryllium fluoroborate) crystal and outputs the fourth harmonic of incident light. The wavelength of the fourth harmonic is approximately 193.4 nm, which is approximately equal to the oscillation wavelength of the ArF excimer laser device.

The solid-state laser control processor 130 is a processing device that includes a memory 130a storing a control program and a CPU 130b that executes the control program. Solid-state laser control processor 130 is specially configured or programmed to perform various processes contained in this disclosure.

Amplifier PA is an ArF excimer laser device including laser chamber 30 , power supply 32 , concave mirror 34 and convex mirror 35 . The configurations of the laser chamber 30 and the power supply device 32 included in the amplifier PA are the same as the corresponding configurations in the laser device 1g described with reference to FIG.

The convex mirror 35 is arranged in the optical path of the pulsed laser light that is output from the master oscillator MO and passed through the laser chamber 30 .
The concave mirror 34 is arranged in the optical path of the pulsed laser light that has been reflected by the convex mirror 35 and passed through the laser chamber 30 again.

The configurations of the monitor module 16 and the laser control processor 13 are similar to the corresponding configurations in the laser device 1 shown in FIGS. 1, 4, 11 and 13.

6.4.2 Operation In the master oscillator MO, the semiconductor laser 160 outputs a CW laser beam with a wavelength of approximately 773.6 nm, and the titanium-sapphire amplifier 171 pulses and amplifies this laser beam and outputs it. The wavelength conversion system 172 converts the pulsed laser light with a wavelength of approximately 773.6 nm into pulsed laser light with a wavelength of approximately 193.4 nm and outputs it toward the amplifier PA.

The pulsed laser light that has entered the amplifier PA passes through the discharge space in the laser chamber 30 , is reflected by the convex mirror 35 , and is given a beam divergence angle according to the curvature of the convex mirror 35 . This pulsed laser light passes through the discharge space in the laser chamber 30 again.

The pulsed laser light that has been reflected by the convex mirror 35 and passed through the laser chamber 30 is reflected by the concave mirror 34 and returned to substantially parallel light. This pulsed laser beam passes through the discharge space in the laser chamber 30 once more, passes through the monitor module 16, and is emitted to the outside of the laser device 1h as the pulsed laser beam Out.

A high voltage is applied to the

electrodes

30a and 30b so that discharge starts in the discharge space within the laser chamber 30 when the pulsed laser light is incident on the laser chamber 30 from the master oscillator MO. The pulsed laser light has its beam width expanded by the convex mirror 35 and concave mirror 34, is amplified while passing through the discharge space three times, and is output to the outside of the laser device 1h.

According to the fourth example, since the single transverse mode pulse laser light output from the master oscillator MO including a solid-state laser is amplified and output, the beam divergence BDV and BDH in the V and H directions can be reduced. It becomes possible. By using such a laser device 1h, the beam divergence BDV and BDH adjustment range of the divergence adjuster 54 can be widened. Moreover, compared with the case where the laser device 1 is used, a smaller hole can be machined.

In the fourth example, the case where the optical resonator included in the amplifier PA is composed of the concave mirror 34 and the convex mirror 35 has been described, but the optical resonator may be a Fabry-Perot resonator or a ring resonator. good.
In the fourth example, the combination of the master oscillator MO that outputs a pulsed laser beam having a wavelength of approximately 193.4 nm and the ArF excimer laser device that amplifies the wavelength component of approximately 193.4 nm has been described. A combination of a master oscillator MO that outputs pulsed laser light having a wavelength of 4 nm and a KrF excimer laser device that amplifies a wavelength component of about 248.4 nm may be used.

In other respects, the laser device 1h may be the same as the laser device 1. Also, the laser device 1h may be provided with a divergence adjuster 20 in the same manner as the laser device 1b.

7. Others FIG. 31 schematically shows the configuration of an electronic device. The electronic device shown in FIG. 31 includes an integrated circuit chip IC, an interposer IP, and a circuit board CS.

An integrated circuit chip IC is, for example, a chip in which an integrated circuit (not shown) is formed on a silicon substrate. The integrated circuit chip IC is provided with a plurality of bumps ICB electrically connected to the integrated circuit.

The interposer IP has an insulating substrate with a plurality of through holes (not shown) formed therein, and each through hole is provided with a conductor (not shown) that electrically connects the front and back sides of the substrate. A plurality of lands (not shown) each connected to the bump ICB are formed on one surface of the interposer IP, and each land is electrically connected to one of the conductors in the through holes. A plurality of bumps IPB are provided on the other surface of the interposer IP, and each of the bumps IPB is electrically connected to one of the conductors in the through holes.

A plurality of lands (not shown) connected to the bumps IPB are formed on one surface of the circuit board CS. The circuit board CS has a plurality of terminals electrically connected to these lands.

FIG. 32 is a flow chart showing a method of manufacturing an electronic device.
In S1, laser processing and wiring formation of the interposer substrate that constitutes the interposer IP are performed. Laser processing of the interposer substrate includes formation of through-holes by irradiating the interposer substrate with the pulsed laser beam Out. Wiring formation includes formation of a conductive film on the inner wall surface of the through hole formed in the interposer substrate. An interposer IP is manufactured through such steps.
At S2, coupling between the interposer IP and the integrated circuit chip IC is performed. This process includes, for example, placing the bump ICB of the integrated circuit chip IC on the land of the interposer IP and electrically connecting the bump ICB and the land.
At S3, coupling between the interposer IP and the circuit board CS is performed. This process includes, for example, placing the bumps IPB of the interposer IP on the lands of the circuit board CS and electrically connecting the bumps IPB and the lands.

The above description is intended as an example, not as a limitation. Accordingly, it will be apparent to those skilled in the art that modifications can be made to the embodiments of the present disclosure without departing from the scope of the claims. It will also be apparent to those skilled in the art that the embodiments of the present disclosure may be used in combination.

Terms used throughout the specification and claims should be interpreted as "non-limiting" terms unless otherwise specified. For example, the terms "including," "having," "comprising," "comprising," etc. are to be interpreted as "does not exclude the presence of elements other than those listed." Also, the modifier "a" should be interpreted to mean "at least one" or "one or more." Also, the term "at least one of A, B and C" shall be interpreted as "A", "B", "C", "A+B", "A+C", "B+C" or "A+B+C", and further and combinations other than "A," "B," and "C."

Claims

a laser device that outputs pulsed laser light;
a divergence adjuster that adjusts a first beam divergence in a first direction and a second beam divergence in a second direction crossing the first direction of the pulsed laser light;
a measuring instrument for measuring the first and second beam divergence of the pulsed laser light that has passed through the divergence adjuster;
a diffractive optical element that branches the pulsed laser beam that has passed through the measuring instrument;
a processor that controls the divergence adjuster so that the first and second beam divergence approaches respective target values based on the measurement results of the first and second beam divergence by the measuring device;
laser processing system, including
The laser processing system according to claim 1,
The first and second beam divergence are greater than the difference between the third beam divergence in the first direction and the fourth beam divergence in the second direction of the pulsed laser beam incident on the divergence adjuster. the difference between the target values of is small,
Laser processing system.
The laser processing system according to claim 1,
further comprising a beam steering device arranged in the optical path of the pulsed laser light between the laser device and the diffractive optical element and adjusting a traveling direction of the pulsed laser light;
The measuring device further measures the beam pointing of the pulsed laser light that has passed through the beam steering device,
The processor controls the beam steering device so that the beam pointing approaches its target value based on the measurement result of the beam pointing by the measuring instrument.
Laser processing system.
The laser processing system according to claim 1,
further comprising a shutter disposed in the optical path of the pulsed laser beam that has passed through the measuring instrument and configured to switch between passing and blocking of the pulsed laser beam;
The processor controls the shutter so that the pulsed laser light is blocked until the measurement results of the first and second beam divergence by the measuring device are within respective allowable ranges including the respective target values. do,
Laser processing system.
The laser processing system according to claim 1,
further comprising a condensing optical system arranged in the optical path of the pulsed laser beam that has passed through the diffractive optical element;
A work piece is positioned at the focal plane of the focusing optics;
Laser processing system.
The laser processing system according to claim 1,
The laser device includes an optical resonator housed in a first housing,
the divergence adjuster and the diffractive optical element are housed in a second housing,
Laser processing system.
The laser processing system according to claim 1,
The laser device includes an optical resonator and the divergence adjuster housed in a first housing,
The diffractive optical element is housed in a second housing,
Laser processing system.
The laser processing system according to claim 1,
a condensing optical system arranged in the optical path of the pulsed laser beam that has passed through the diffractive optical element;
a mask disposed at the focal plane of the condensing optical system and having a plurality of apertures;
a projection optical system arranged in an optical path of the pulsed laser beam that has passed through the mask;
The laser processing system, further comprising:
The laser processing system according to claim 8,
the condensing optical system converges the branched light beams so that cross sections of the plurality of branched beams of the pulsed laser beam branched by the diffractive optical element overlap with the plurality of apertures, respectively;
Laser processing system.
The laser processing system according to claim 1,
a condensing lens arranged in an optical path of the pulsed laser beam that has passed through the measuring instrument and condensing the pulsed laser beam;
a mask placed in the optical path of the pulsed laser beam that has passed through the condenser lens;
a collimator optical system arranged in the optical path of the pulsed laser light between the mask and the diffractive optical element;
further comprising
Laser processing system.
A laser processing system according to claim 10,
wherein the mask is positioned at the focal point of the condenser lens;
Laser processing system.
A laser processing system according to claim 10,
further comprising a condensing optical system arranged in the optical path of the pulsed laser beam that has passed through the diffractive optical element;
projecting the image of the mask onto a plurality of positions of the workpiece with the collimator optical system, the diffractive optical element, and the condensing optical system;
Laser processing system.
The laser processing system according to claim 1,
wherein the divergence adjuster is configured to adjust beam divergence angles in the first and second directions;
Laser processing system.
The laser processing system according to claim 1,
wherein the divergence adjuster is configured to adjust beam widths in the first and second directions;
Laser processing system.
The laser processing system according to claim 1,
The divergence regulator is
first and second cylindrical convex lenses that condense the pulsed laser light in the first and second directions, respectively;
a collimator lens for collimating the pulsed laser light condensed by the first and second cylindrical convex lenses;
laser processing system, including
16. The laser processing system of claim 15,
The divergence adjuster is variable for adjusting the beam width in either one of the first and second directions by blocking part of the pulsed laser light incident on the first and second cylindrical convex lenses. further comprising a slit;
Laser processing system.
16. The laser processing system of claim 15,
The divergence adjuster further includes first and second linear stages that move the first and second cylindrical convex lenses along the traveling direction of the pulsed laser light, respectively.
Laser processing system.
The laser processing system according to claim 1,
wherein the divergence adjuster includes an optical pulse stretcher configured to split the optical path of the pulsed laser light in one of the first and second directions;
Laser processing system.
A pulsed laser beam is output from the laser device,
The pulsed laser light is incident on a divergence adjuster that adjusts a first beam divergence in a first direction and a second beam divergence in a second direction crossing the first direction of the pulsed laser light. let
measuring the first and second beam divergence of the pulsed laser light that has passed through the divergence adjuster with a measuring instrument;
controlling the divergence adjuster so that the first and second beam divergence approaches respective target values based on the measurement results of the first and second beam divergence by the measuring instrument;
A laser processing method, comprising splitting the pulsed laser beam that has passed through the measuring device by a diffractive optical element and irradiating the workpiece with the pulsed laser beam.
A method for manufacturing an electronic device,
a laser device that outputs pulsed laser light;
a divergence adjuster that adjusts a first beam divergence in a first direction and a second beam divergence in a second direction crossing the first direction of the pulsed laser light;
a measuring instrument for measuring the first and second beam divergence of the pulsed laser light that has passed through the divergence adjuster;
a diffractive optical element that branches the pulsed laser beam that has passed through the measuring instrument;
a processor that controls the divergence adjuster so that the first and second beam divergence approaches respective target values based on the measurement results of the first and second beam divergence by the measuring device;
An interposer is produced by laser processing the interposer substrate with a laser processing system including
coupling and electrically connecting the interposer and the integrated circuit chip together;
A method of manufacturing an electronic device, comprising combining and electrically connecting the interposer and the circuit board to each other.